The following relates generally to wireless communications, and more specifically to sideband-based self-calibration of an array antenna system.
Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code-division multiple access (CDMA), time-division multiple access (TDMA), frequency-division multiple access (FDMA), orthogonal frequency-division multiple access (OFDMA), or discrete Fourier transform-spread-orthogonal frequency-division multiplexing (OFDM) (DFT-s-OFDM). A wireless multiple-access communications system may include a number of base stations or network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE).
Some wireless communications systems, such as NR systems, may use high-frequency signals and an array of antenna elements to form directional communication links, and may communicate data via the directional communications link. For example, a phased array antenna system (e.g., a communications system that may process, transmit, and receive signals via a phased array antenna) may be configured to generate and steer (point) the directional communication links in different directions by manipulating phase and/or amplitude relationships between signals transmitted and received by the individual antenna elements of the phased array antenna. For example, the phased array antenna system may be configured to point one or more beams at a target during operation. The constituent antenna elements of the phased array antenna are typically closely packed, and the small distance between the antenna elements has the potential to affect not only their radiation pattern, but may also contribute to mutual coupling between them, which may increase interference and/or degrade performance.